US4493778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water-based magnetic coating composition
Assignee: Memorex Telex NV
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Filing: 1982-07-14
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Granted: 1985-01-15
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Expires: 2002-07-14
Abstract
Abstract Disclosure is made of an improved aqueous magnetic coating composition employing a polyacrylic latex polymer as a dispersant. As preferred embodiments, the composition further comprises a polymeric binder having both hard and soft components, as well as the inclusion of flow agents, antifoaming agents, wetting agents and lubricants.
Inventors
- 👤 Sikandar Iqbal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:27
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/7013; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
113 words
In an aqueous coating composition for forming a magnetic recording layer, this layer including magnetic pigment material and a water-based polymeric matrix therefor, this matrix including binder material comprising high molecular weight poly blends of hard and soft polymers adapted to form "interpenetrating elastomeric networks" in the presence of the magnetic pigment; the improvement comprising the use of sufficient polyacrylic latex polymer, as a dispersant in an aqueous solution to which the pigment is added, to adequately stabilize the pigment material, after mixing, and bond it to the binder material with little or no migration to the surface of the finished recording layer, and also so as to avoid flocculation and aggravated foaming.
Claim 2
Dependent Claim
113 words
In an aqueous coating composition for forming a magnetic recording layer, this layer including magnetic pigment material and a water-based polymeric matrix therefor, this matrix including binder material comprising high molecular weight poly blends of hard and soft polymers adapted to form "interpenetrating elastomeric networks" in the presence of the magnetic pigment; the improvement comprising the use of sufficient polyacrylic latex polymer, as a dispersant in an aqueous solution to which the pigment is added, to adequately stabilize the pigment material, after mixing, and bond it to the binder material with little or no migration to the surface of the finished recording layer, and also so as to avoid flocculation and aggravated foaming.
Claim 3
Dependent Claim
30 words
The aqueous coating composition of claim 1 wherein the polyacrylic latex polymer comprises a terpolymer including styrene and a member selected from the group consisting of butyl acrylate and methylmethacrylate.
Claim 4
Dependent Claim
41 words
The aqueous coating composition of claim 2 wherein styrene is present in the polyacrylic latex in an amount between approximately 10-20% by weight and the remaining acrylate is present in the polyacrylic latex in an amount between approximately 80-90% by weight.
Claim 5
Dependent Claim
20 words
The aqueous coating composition of claim 2 wherein said copolymer is of a molecular weight between approximately 20,000 to 40,000.
Claim 6
Dependent Claim
22 words
The aqueous coating composition of claim 1 further comprising a water insoluble polymeric binder having both a hard and a soft component.
Claim 7
Dependent Claim
32 words
The aqueous coating composition of claim 5 wherein the hard component comprises a member selected from the group consisting of copolymers and terpolymers of acrylonitrile, ethyl acrylate, butylacrylate, methylmethacrylate and mixtures thereof.
Claim 8
Dependent Claim
38 words
The aqueous coating composition of claim 6 wherein the hard component comprises a copolymer of approximately 10-20% by weight of acrylonitrile and approximately 80-90% by weight of a member selected from the group consisting of ethylacrylate and butylacrylate.
Claim 9
Dependent Claim
34 words
The aqueous coating composition of claim 6 wherein the hard component comprises a terpolymer of approximately 6-20% by weight of acrylonitrile, approximately 60-80% by weight ethylacrylate or butylacrylate and approximately 10-20% by weight methylmethacrylate.
Claim 10
Dependent Claim
31 words
The aqueous coating composition of claim 5 wherein the soft component comprises a polymer emulsion of a polyurethane having a glass transition temperature of between approximately -10° C. to -40° C.
Claim 11
Dependent Claim
18 words
The aqueous coating composition of claim 5 further comprising a flow agent, antifoaming agent, wetting agent and lubricant.
Claim 12
Dependent Claim
21 words
The aqueous coating composition of claim 10 wherein said flow agent is an alkyline-soluble emulsion of ethyl acrylate and acrylic acid.
Claim 13
Dependent Claim
51 words
The aqueous coating composition of claim 10 wherein said lubricant comprises a member selected from the group consisting of aliphatic and aromatic stearates, silicone oils, perfluoro alkyl polyethers and fluorinated fluids having one of the following structures: ##STR2## wherein n=40-90 m=40-90 and F--CF(CF.sub.3)CF.sub.2 O].sub.n' C.sub.2 F.sub.5 wherein N'=14-45 and mixtures thereof.
Claim 14
Dependent Claim
59 words
The aqueous coating composition of claim 1 wherein the polyacrylic latex dispersant polymer comprises a terpolymer of styrene and a member selected from the group consisting of butyl acrylate and methylmethacrylate, wherein the binder material is comprised of high molecular weight latexes of hard and soft polymers adapted to form "interpenetrating elastomeric networks" in the presence of magnetic pigment.
Claim 15
Dependent Claim
53 words
The aqueous coating composition of claim 13 wherein styrene is present in the polyacrylic latex in an amount between approximately 10-20% by weight and the remaining acrylate is present in the polyacrylic latex in an amount between approximately 80-90% by weight, with said copolymer having a molecular weight between approximately 20,000 to 40,000.
Claim 16
Dependent Claim
33 words
The aqueous coating composition of claim 14 wherein the hard component polymer comprises a member selected from the group consisting of copolymers and terpolymers of acrylonitrile, ethyl acrylate, butylacrylate, methylmethacrylate and mixtures thereof.
Claim 17
Dependent Claim
38 words
The aqueous coating composition of claim 15 wherein the hard component comprises a copolymer of approximately 10-20% by weight of acrylonitrile and approximately 80-90% by weight of a member selected from the group consisting of ethylacrylate and butylacrylate.
Claim 18
Dependent Claim
32 words
The aqueous coating composition of claim 14 wherein the soft component polymer comprises a polymer emulsion of a polyurethane having a glass transition temperature of between approximately -10° C. to -40° C.
Claim 19
Dependent Claim
62 words
The aqueous coating composition of claim 14 wherein the soft component polymer comprises a polymer emulsion of a polyurethane having a glass transition temperature of between approximately -10° C. to -40° C.; and wherein this aqueous coating composition further comprises a flow agent, antifoaming agent, wetting agent and lubricant; said flow agent comprising an alkyline-soluble emulsion of ethyl acrylate and acrylic acid.
Claim 20
Dependent Claim
51 words
The aqueous coating composition of claim 18 wherein said lubricant comprises a member selected from the group consisting of aliphatic and aromatic stearates, silicone oils, perfluoro alkyl polyethers and fluorinated fluids having one of the following structures: ##STR3## wherein n=40-90 m=40-90 and F--CF(CF.sub.3)CF.sub.2 O].sub.n' C.sub.2 F.sub.5 wherein n'=14-45 and mixtures thereof.
Claim 21
Dependent Claim
30 words
The aqueous coating composition of claim 6 wherein the hard component comprises a copolymer or terpolymer of approximately 10-20% by weight of acrylonitrile and approximately 90-80 wt.% ethylacrylate or butylacrylate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-15 | 1988-07-16 | 1989-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-15 | 1992-07-16 | 1993-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-15 | 1996-07-16 | 1997-01-15 | $7700.00 | Window Closed / Lapsed |